Database Users

[Q] Kernel - ROM Compatibility

I'd like to try flashing a new Kernel. I rooted my Evo using Unrevoked3. My guess is is that not all kernels are compatible with every ROM. I'm using a stock ROM, and I'm interested in trying the Kings 6 BFS kernel. Are there info pages on each kernel that would answer such questions? I tried searching for Kings 6 Kernel and came up dry.

*most* kernels will work with most roms, but not all the time. Sometimes, like with the netarchy-toastmod kernels, they have been optimized for use with a specific rom, like Fresh or Damage control. This is part of the reason why kernel coders always put the disclaimer that they are not responsible for anything that might go wrong with your phone. They can't forsee all possible unique user setups, so there might always be the off chance that some particular combination will result in your phone melting.
What I did, was get the rom I wanted, make a new nandroid backup, and start trial and error. I use them for a few days to see how performance, battery life, etc. are working, then try a different one.

[Q] Rooting, flashing custom rom but necessary to flash a kernel as well?

Hi,
Quick question I am still having trouble wrapping my head around the concept about kernels. I am planning to root my nexus 4 and flash a custom rom (purity rom) but am i required to also flash a custom kernel? Or am I suppose to leave the kernel as is?
Thanks!

Next123 said:
Hi,
Quick question I am still having trouble wrapping my head around the concept about kernels. I am planning to root my nexus 4 and flash a custom rom (purity rom) but am i required to also flash a custom kernel? Or am I suppose to leave the kernel as is?
Thanks!
Click to expand...
Click to collapse
Depends upon your requirement .
As an example i use Fast USB charge a lot and is not available in any custom rom .
I also use Headphone volume boost which is yet again a kernel level change.
I would suggest you to use a custom kernel since it also gives better battery than stock .
If you are happy without it then forget about kernels . And in case u plan on flashing one make a CWM backup just in case.,

You could if you want to since you're already flashing custom roms. However, most custom rom come with custom kernel, so when you flash a custom rom it will replace your kernel with it's own. You can manually flash back your stock kernel if you want, using fastboot, but there is a flashable package as well in the Dev section.
Just know that due to codes and drivers, different kernels work with different roms. If you flash a 4.3 kernel to a 4.4 rom, it might lack certain necessary driver, such as PRIMA, so your wifi will no longer work. (You can fix this by flashing dePRIMAtor). CyanogenMod use Code Aurora Forum drivers, so if you use a kernel that doesn't support CAF, the screen colors will be messed up (you can lash a colorfix package which replace it with the non-CAF liboverlay.so).
A lot of people get wrapped too far up into flashing kernel and thinking it determine everything (performance + battery life) in their phone. As much of a heavy flasher that I am, I am willing to bet that you generally get the best battery life and stability just running stock. I did my own trial for this, with stock rom and kernel, the phone staying cooler and screen on time was longer. This is just my personal experience, it varies for each person.
But I mainly use custom kernel for features. Such as kernels that incorporate Faux color and sound, this allows changing their settings for much a better screen color and making the speaker louder. I also use the sweep2wake/sleep feature to turn on and off the screen.
If you intend to use custom kernels, I recommend using TricksterMod, it's the best app for modifying kernel settings.
Also just to mention this ahead of time, it's against XDA rules to make threads about what is the best rom/kernels.

Best ROM to use on MXP

I am just wondering how many people like the actual STOCK rom and cyanogen based ROM
So I am making a poll to see which one get's more vote
P.S this is not related to someone's specific ROM..
As we all know, some people like to keep STOCK as it is and some like modifications and customizations.
Stock means pure stock experience with root (OBviously) and Some like CyanogenMod ROM or based on it.
This is a poll to know what most users like.

Stock in this case means a very stable bug-free ROM with some nice features, like Moto Display. The little bloatware is gone after root. And you cans still get the customizations you want through custom kernels, Layers and/or Xposed !

Why install a custom rom on gs7?

Hi,
This question is mostly towards the people that have already installed a custom rom on their GS7.
I have a GS7 G935F model and i was wondering why you guys choose to installed custom rom?
I'm a big fan of custom roms. I have used them in the past on my GS3 T999, because T-mobile didn't release any new updates for the phone. I saw the need to use a custom rom to be on the latest and greatest version and i switched from rom the rom to test witch one suited me best. Now with the GS7 i get frequent updates from samsung and don't see the need, but i'm still really really interested in trying one of the custom roms. So what else does a custom bring that will make me want to make that switch?

JurrienXR said:
Hi,
This question is mostly towards the people that have already installed a custom rom on their GS7.
I have a GS7 G935F model and i was wondering why you guys choose to installed custom rom?
I'm a big fan of custom roms. I have used them in the past on my GS3 T999, because T-mobile didn't release any new updates for the phone. I saw the need to use a custom rom to be on the latest and greatest version and i switched from rom the rom to test witch one suited me best. Now with the GS7 i get frequent updates from samsung and don't see the need, but i'm still really really interested in trying one of the custom roms. So what else does a custom bring that will make me want to make that switch?
Click to expand...
Click to collapse
most of those frequent updates are for security propose.
custom roms enable you to unlimited experience of customization.
changing any system ui element or installing some apps that need root access and works better on custom roms usually.
but some app or mod you install on custom rom have risks to brick your phone and you need to prepare urself to repair it or search a lot to get stable ones.
:good:

Geeks Empire said:
most of those frequent updates are for security propose.
custom roms enable you to unlimited experience of customization.
changing any system ui element or installing some apps that need root access and works better on custom roms usually.
but some app or mod you install on custom rom have risks to brick your phone and you need to prepare urself to repair it or search a lot to get stable ones.
:good:
Click to expand...
Click to collapse
Changing system ui elements or using root apps/ modules. 3 years ago u needed a custom rom for a new look and extra functionality that wasn't normally possible. Nowadays most of those things are possible. I'm searching for the things i can do now if i choose to install a custom rom. Things i could really use.
Which root apps or modules do u use on your phone?

Basic Qs about Custom Kernels and ROMS

I've been mucking around with Android for a while but basically stay with a ROM and what it comes packaged (or recommended) with.
Recently I've been looking around at Custom Kernels and I see they offer different options and functionality, but I lack some basic information:
I am guessing that the Kernel and ROM have to be compatible?
Is, for example a Kernel like Blu Spark or Lighting (all for OP5 and Nougat) compatible with all OP5 Nougat ROMs or is it ROM by ROM?
I looked over the pages for both Kernels and also for xXx Freedom OS and didn't see any information concerning compatible ROMs or compatible Kernels, is there any place/list that shows the compatibility of ROMs and Kernels?
Any information, or guidance to where I can find it would be appreciated.

Very simple.
There are 2 types of kernels. One which only works on an OOS based (custom) Rom, and one which will only work on a LOS or AOSP based Rom. Most custom kernels will work on every LOS or AOSP based ROM. But... There's one negative thing about flashing custom or OOS based Kernels. You will never know how the Kernel and/or ROM will behave. There's no 100 percent guarantee if a custom Kernel or ROM are made for each other. Even if a Kernel which comes with the ROM is no guarantee for working properly. There's no such thing as "Stable" even with ROMs. Because stable doesn't exist in a Dev World. It will always be a never ending story.
Long story short, search for yourself an satisfying combination. If you found one combination you like, stick with it and motivate the Custom ROM Developer and or Kernel Developer.
Edit: as you can read i cannot give a proper answer to your questions. The reason why a Custom ROM Dev doesn't show a list in their OP for working Custom Kernels, is mainly based on the fact that they don't like if a user flash another Kernel that didn't came with their ROM. Mostly to avoid non related ROM issues. Besides that, if you made a decision to flash a Different kernel, along with their ROM, you're on your own.
Sorry for being off-topic.

Each kernel needs to be build for each rom. Well not each rom. Each rom based on the top three. OOS, AOSP, and LOS. As each has their own kernel.
If you use LOS 14.1 or RR, then youll need a los kernel. If you run stock OOS. Freedom or xXx, youll need an oos based kernel
Not all devs build their kernels for los or aosp. Me as an example. I only have mine built for OOS and It wont work on los or aosp (well it may but you are 99.999% likely to run into a lot of problems)
I hope that clears it up a tad bit

lekiaM said:
Very simple.
There are 2 types of kernels. One which only works on an OOS based (custom) Rom, and one which will only work on a LOS or AOSP based Rom. Most custom kernels will work on every LOS or AOSP based ROM. But... There's one negative thing about flashing custom or OOS based Kernels. You will never know how the Kernel and/or ROM will behave. There's no 100 percent guarantee if a custom Kernel or ROM are made for each other. Even if a Kernel which comes with the ROM is no guarantee for working properly. There's no such thing as "Stable" even with ROMs. Because stable doesn't exist in a Dev World. It will always be a never ending story.
Long story short, search for yourself an satisfying combination. If you found one combination you like, stick with it and motivate the Custom ROM Developer and or Kernel Developer.
Edit: as you can read i cannot give a proper answer to your questions. The reason why a Custom ROM Dev doesn't show a list in their OP for working Custom Kernels, is mainly based on the fact that they don't like if a user flash another Kernel that didn't came with their ROM. Mostly to avoid non related ROM issues.
Click to expand...
Click to collapse
@lekiaM You provided a great answer and thank you. I did notice that some developers (xXx NoLimits) provide the option to select various Kernel during the install. I pretty much expected that matching a Rom to Kernel was a crap shoot to certain degree. I am going to try a few out and see how it goes.
One final question, if a Kernel offers functionality that is not offered in the original Kernel, how do you go about taking advantage of the added functionality?
Will the Kernel add those selection to the settings or will I need a different app to access them? I was thinking in particular of the don't wake on plug/unplug. I utilized some ROMs (CM) that had this feature in the setting, I use Freedom OS now and don't see that in the setting, but I see that the Blu Spark Kernel offers access to that function.

Zombie said:
Each kernel needs to be build for each rom. Well not each rom. Each rom based on the top three. OOS, AOSP, and LOS. As each has their own kernel.
If you use LOS 14.1 or RR, then youll need a los kernel. If you run stock OOS. Freedom or xXx, youll need an oos based kernel
Not all devs build their kernels for los or aosp. Me as an example. I only have mine built for OOS and It wont work on los or aosp (well it may but you are 99.999% likely to run into a lot of problems)
I hope that clears it up a tad bit
Click to expand...
Click to collapse
It does thanks. Prior to selecting some ROMs to try, I read that AOSP required a specific ROM so I steered away from it, for now. Until I am able to become a little more familiar with the entire subject.

noncomjd said:
It does thanks. Prior to selecting some ROMs to try, I read that AOSP required a specific ROM so I steered away from it, for now. Until I am able to become a little more familiar with the entire subject.
Click to expand...
Click to collapse
An aosp based rom will install and run like any other rom you decide to flash. It comes with the stock kernel built in
Each rom has their advantages and disadvantages. Currently Im running xXx 4.0 which is OOS based with extra features and then of course my own kernel for better performance and battery

@noncomjd Good question. And honestly I've been wondering that too (most of the time) i could gave you a simple answer on that, but i wont.
A Kernel can interfere with the ROMs behavior (for example manipulate the vibration, sounds, led light strength, button behavior and so on.) But a Kernel has their limits too and also the Kernel Dev in question. Besides that , i did saw some very strange things a Kernel Dev can do to manipulate a ROMs behavior. But i wont go further in that.
Answer to your question:
Yes. A good kernel dev can overwrite or add some tweaks in the ROM itself (you won't see it while flashing, but believe me after that, some things in settings are missing or added in the build.prop) . But as i earlier said it has their limits. A good Kernel Dev is aware of their capabilities. And they mostly play save. If a kernel Dev mentioned or added a feature or something in their changelog, than the feature is there. But to enable or disable that feature, you mostly need an 3rd party app(like a Kernel Manager) to activate or deactivate their added feature.

You need a kernel tweaking app in order to change kernel settings.
You can change those settings even if you run the stock kernel, but it won't offer as much features.
There are many kernel tweaking apps available and some kernels even provide their own apps.

Thanks all for some great information. Have a good base to set out exploring a little more.